The way the game is designed, it's certainly possible to get through the game with just Chrom and the avatar. Definitely on normal, possibly on hard too.

Stat boost from pair up, a sufficient amount of healing items early on, plenty of money to stock up on everything you need, soon outleveling enemies due to the focus on only two characters, optionally using permanent stat boosters to reduce weaknesses further. And since Chrom takes the entire storage with him, five item slots per character aren't an issue at all, because you can refresh your inventory or adjust it on the fly.

Paralogue 17 (protect Tiki) would be impossible with just two characters, but it's not required to beat the game. The only main story map where you have to protect someone is chapter 6, but by the time you get there the two characters should be powerful enough to wipe out the thieves early on and then move to the open entrance of Emmeryn's room to block it. Or one character stays near Marth while the other one heads down on the West side, eventually taking care of the boss.

Might actually be worth trying out. Such a file should be doable in around ten hours.

Pressing X immediately after the battle starts on a unfamiliar map is pretty much mandatory as is highlighting the enemies if there are any enemies equipped with weapons/magic that have the advantage over some of your units (i.e. a enemy equipped with a Hammer or a mage with wind magic) so that you know where not to place them.

The way the game is designed, it's certainly possible to get through the game with just Chrom and the avatar. Definitely on normal, possibly on hard too.

Stat boost from pair up, a sufficient amount of healing items early on, plenty of money to stock up on everything you need, soon outleveling enemies due to the focus on only two characters, optionally using permanent stat boosters to reduce weaknesses further. And since Chrom takes the entire storage with him, five item slots per character aren't an issue at all, because you can refresh your inventory or adjust it on the fly.

Paralogue 17 (protect Tiki) would be impossible with just two characters, but it's not required to beat the game. The only main story map where you have to protect someone is chapter 6, but by the time you get there the two characters should be powerful enough to wipe out the thieves early on and then move to the open entrance of Emmeryn's room to block it. Or one character stays near Marth while the other one heads down on the West side, eventually taking care of the boss.

Might actually be worth trying out. Such a file should be doable in around ten hours.

Oh, is that a challenge? Fine then.

Here are the conditions:

1) Normal difficulty.
2) Only Chrom and the avatar can be used. Other characters will be benched, although if you insist I'll kill them. For gameplay, the result is the same for both, but killing characters will take more time.
3) Only the main story has to be completed, meaning the 27 chapters spanning from prologue to final. No paralogues.
4) No grinding, meaning no other maps than the main story chapters are allowed to be played.
5) Renown rewards and money can be used how I see fit.

If you agree to these conditions, I'll start such a file and will keep you updated. I am convinced that I can do it and that I can do it in ten hours or less.

Huh. That was...quick.

I told you it would take less than ten hours. The pair up mechanic truly breaks the game beyond belief, hence why garbage difficulty settings like lunatic and lunatic+ had to be included. I am not enjoying the game at all on lunatic. I ended up buying the EXP DLC (a late night decision), but that doesn't solve the problem. Lunatic is more or less Fire Emblem: Disgaea Edition.

The solution is to get the rescue staff from paralogue 1, pair up Ricken and Maribelle, then have them rescued by Lissa.